1. Field of the Invention
This invention relates to a portable game apparatus with an acceleration sensor and information storage medium storing a game program, and more particularly to a portable game apparatus and information storage medium storing a game program wherein tilting or movement of the portable game apparatus is detected by an acceleration sensor and utilized as operational information for game control.
2. Description of the Prior Art
The conventional portable game apparatuses have an input device, such as a cross key and push button so that a player can manipulate the input device while holding the portable game apparatus by hand, thereby enabling game character movement and command selection.
There are prior art devices, as disclosed in Japanese Patent Laid-open No. H8-191953 and Japanese Patent Laid-open No. H10-21000, that utilize, as a game input device, a tilt sensor or acceleration sensor. In such prior art devices, the tilt or acceleration sensor is provided on a controller which is separate from a game machine main body so as to detect movement or tilt of the controller. This allows a player to control game characters being displayed on a TV screen by moving or tilting the controller.
However, the above-described prior art devices are not directly applicable to a portable game apparatus. This is because the acceleration sensor or the like is added on the video game apparatus controller having a display, such as a television receiver, separate from the game apparatus main body. The portable game apparatus includes a display, such as an LCD, and adapted to be gripped for game play on housing ends by the hands of the user. It is a usual practice for the player to play a game while holding the portable game apparatus such that it has a tilt relative to the horizontal position, in a manner facilitating viewing of the LCD display. However, when the portable game apparatus is tilted relative to the horizontal, the acceleration sensor would detect acceleration even when no intentional acceleration input (or tilt input) is given by the player. In addition, the tilt angle of a portable game apparatus differs due to a variety of factors, such as a difference between individual players, light source position of electric light or the like, game content, player""s game playing posture, and so on.
It is therefore a primary object of the present invention to provide a novel portable game apparatus with an acceleration sensor.
Another object of the invention is to provide a portable game apparatus with an acceleration sensor which can set as a neutral position a tilted position of the portable game apparatus used by a player, so that the player can hold it with a desired tilt that makes it easy to play a game.
Another object of the invention is to provide an information storage medium for a portable game apparatus with an acceleration sensor that stores a game program capable of setting a neutral position.
Still another object of the invention is to provide a game cartridge which can control for a game based on an output of an acceleration sensor that is simple in structure and low in cost, even where the portable game apparatus has already been produced.
A portable game apparatus according to the present invention, includes: a housing to be gripped by a hand of a player; a display arranged in one main surface of the housing to display game scenes; an acceleration sensor movable with the housing; a neutral position setter for setting a reference tilt position for the housing; a temporary storage for temporarily storing as a neutral position data an output value of the acceleration sensor corresponding to the neutral position; a corrector for correcting an output value of the acceleration sensor based on the neutral position data; and a game controller for changing a display state of a game scene to be displayed on the display based on an output value of the corrector.
Specifically, the neutral position setter includes an operation key to be operated by the player, and a program to write as the neutral position data into the temporary storage a corresponding output value of the acceleration sensor to a tilt of the housing when the player operates the operation key.
In another embodiment, the neutral position setter includes a sight display to display on the display a sight movable depending upon a tilt of the housing, and a target coordinate display to display on the display a target coordinate that the sight is to position or when the housing is in a proper tilted position, wherein the neutral position data is set by a corresponding output value of the acceleration sensor to a tilt of the housing when the sight overlaps with the target coordinate.
In this embodiment, the game scene is a scene constituted by game characters (player characters, ally characters, enemy characters and stationary characters, etc.), an environment where the game character exist (xe2x80x9cwaterxe2x80x9d for the presence of the game character underwater, etc.) and a background. The game controller varies a state of these items. For example, the player character or enemy character is displayed with movement or shape change, or the environment or background is varied or scrolled on the display.
In the portable game apparatus of the invention, prior to game play, a reference tilt of the portable game apparatus is set by the neutral position setter. The reference tilt may be set arbitrarily by the player or at a tilt previously determined by a program. Alternatively, the player may select any one of a plurality of tilts previously determined by a program. For example, where the player sets an arbitrary tilt, the player holds the portable game apparatus with a desired tilt that makes it easy to play a game and then manipulates an operation key. Thereupon, an output value of the acceleration sensor upon operating the operation key is written and held as neutral position data into the temporary storage. During the game, the output value of the acceleration sensor is corrected based on the neutral position data by the corrector. Then, the game controller changes a display state of the game scene according to the corrected acceleration sensor output. Incidentally, the neutral position setter may be configured such that a neutral position can be set in the course of game play.
According to the invention, in the portable game apparatus with an acceleration sensor, it is possible to set as a neutral position a tilt given when the player grips the portable game apparatus.
An information storage medium according to the present invention is a storage medium to be loaded on a portable game apparatus, having a display to display game scenes, a housing to be gripped by a hand of a player and arranged with the display on one main surface thereof, a processor, and stored information to be processed by the processor, including: an acceleration sensor output read program to read out an output value of the acceleration sensor; a neutral position set program for setting a reference tilt of the portable game apparatus; a write program for writing as neutral position data to a temporary storage memory a corresponding output value of the acceleration sensor to the neutral position; a correction program for correcting the acceleration sensor output value by the neutral position data; and a game control program for changing a display state of the game scene to be displayed on the display based on an output value of the correction program.
In this embodiment, prior to game play, the neutral position set program sets a reference tilt of the portable game apparatus. The acceleration sensor output read program reads out a corresponding acceleration output value to the set neutral position, and the write program writes it as neutral position data to the temporary storage. This temporary storage may be a storage in the information storage medium or a storage in the portable game apparatus. In game play, the acceleration sensor output read program reads out an acceleration sensor output value to proceed with a game process. However, the acceleration sensor output value is corrected based on the neutral position data and thereafter the game control program changes a display state of game scene.
The acceleration sensor is provided related the housing. More specifically, the information storage medium is a cartridge that can be loaded into and unloaded from the housing of the portable game apparatus, and the acceleration sensor being accommodated in the cartridge.
If the acceleration sensor is accommodated in the cartridge in this manner, it is possible to perform processing based on an acceleration sensor output with a simple structure and at low cost even where the portable game apparatus has been produced.
In the case that the portable game apparatus includes an operation key, the write program writing as the neutral position data to the temporary storage memory a corresponding output value of the acceleration sensor to a tilt of the housing when the player operates the operation key.
Furthermore, the neutral position set program includes a sight display program to display on the display a sight movable depending upon the tilt of the housing, and a target coordinate display program to display on the display a target coordinate that the sight is to be positioned on when the housing is in a proper tilt, and the neutral position data being set by a tilt of the housing when the sight overlaps with the target coordinate.
In another aspect of the invention, there is provided a portable game apparatus having a display arranged on one main surface thereof, including: a game map data storage for storing game map data to display on the display a game map as a background image; a game character data storage for storing game character data to display on the display a game character; an acceleration sensor for detecting an acceleration to thereby detect a change amount depending upon movement or tilt of the portable game apparatus; a program storage for storing program data to move and display the game character depending upon at least a tilt direction detected by the acceleration sensor; and a processor for displaying a game image on the display in a manner that changes a display state of the game character by processing based on an output of the acceleration sensor and the program.
In this portable game apparatus, the processor processes a program according to an output of the acceleration sensor whereby the game character on the display can be varied (moved, deformed) according to the acceleration sensor output.
For example, the acceleration sensor is operable to detect an acceleration due to an abrupt movement of the portable game apparatus and detects at least one of a tilt amount and a tilt direction due to a moderate tilt thereof. The program storage includes a program to move and display the game character in a manner that changes a moving amount based on a tilt amount as a detection output of the acceleration sensor.
In this case, the program storage includes a program to vary a change amount of the game character depending upon an acceleration of a detection output of the acceleration sensor.
In one embodiment, the game map data storage further stores as a game map a plurality of kinds of lands of data, at least one of the plurality of kinds of lands being a land to have an effect upon a change amount in movement of the game character, and the program storage includes a program to move and display the game character in a manner which controls a change amount of movement thereof when the game character is present on the land, wherein the land has an effect upon the movement.
The game map data storage stores game map data having an area greater than a display area of the display, the game character data storage storing data to display a player character to be operated by the player, and the program storage displaying on the display one area of the game map near the player character, and including a game map movement display program to display the one area with scrolling in accordance with movement of the player character.
In the case that the game character data storage further stores non-player character data to display at least one of non-player characters not to be moved by the player, the program storage further storing a program to move by self-control at least one of the non-player characters.
The program storage further includes an impact determination program to determine a presence of an impact input based on an output of the acceleration sensor in magnitude equal to or greater than a given value.
Specifically, the acceleration sensor includes an acceleration detecting section to detect respective accelerations in first and second directions perpendicular to each other to thereby output a first output value dependent upon an acceleration in the first direction and a second output value dependent upon an acceleration in the second direction, and the impact determination program determines a presence of an impact input when a resultant vector having a vector component in the first direction taken by the first output value and a vector component in the second direction taken by the second output value is equal to or greater than a given value.
Movement of the game character is displayed with a greater moving amount than that of a movement of display based on a program when the impact determination program determines a presence of an impact input. Alternatively, the game character is displayed with an inverted position when the impact determination program determines a presence of an impact input.
In the case that the game character is displayed in a manner of moving over and along the background image, the program storage simulating a tilt of the background image depending upon a tilt of the portable game apparatus to display the game character in a manner of moving over and along the background image depending upon a tilt direction of the background image.
In a still another aspect of the invention, there is provided an information storage medium to be used on a portable game apparatus including a display to display game scenes, a housing to be gripped by a hand of a player and arranged with the display in one main surface thereof, and a processor, including: a game map data storage for storing game map data to display on the display a game map as a background image; a game character data storage for storing game character data to display on the display a game character; an acceleration sensor for detecting a change amount depending upon a movement or tilt of the portable game apparatus due to detection of an acceleration; and a program storage for storing program data to move and display the game character depending upon at least a tilt direction detected by the acceleration sensor, wherein the processor performs processing based on an output of the acceleration sensor and the program thereby controlling a game image displayed on the display such that a display state of the game character is varied depending upon an acceleration.
In one embodiment, the acceleration sensor detects an acceleration due to an abrupt movement of the portable game apparatus and detects at least one of a tilt amount and a tilt direction due to a moderate tilt thereof, and the program storage including a program to move and display the game character in a manner which changes a moving amount based on a tilt amount as a detection output of the acceleration sensor.
The above described objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.